hidtools.uhid module

class UHIDDevice

Bases: object

A uhid device. uhid is a kernel interface to create virtual HID devices based on a report descriptor.

This class also acts as context manager for any UHIDDevice objects. See dispatch() for details.

device_nodes

A list of evdev nodes associated with this HID device. Populating this list requires udev events to be processed, ensure that dispatch() is called and that you wait for some reasonable time after creating the device.

hidraw_nodes

A list of hidraw nodes associated with this HID device. Populating this list requires udev events to be processed, ensure that dispatch() is called and that you wait for some reasonable time after creating the device.

uniq

A uniq string assigned to this device. This string is autogenerated and can be used to reliably identify the device.

UHID_FEATURE_REPORT = 0
UHID_INPUT_REPORT = 2
UHID_OUTPUT_REPORT = 1
property bus

The device’s bus type (0x3 for USB, 0x5 for Bluetooth, etc.)

call_input_event(data)

Send an input event from this device.

Parameters

data (list) – a list of 8-bit integers representing the HID report for this input event

close()

Called when a userspace client closes the created kernel device.

Sending events on a closed device will not result in anyone reading it.

This message is sent by the kernel, to receive this message you must call dispatch()

create_kernel_device()

Create a kernel device from this device. Note that the device is not immediately ready to go after creation, you must wait for start() and ideally for open() to be called.

Raises

UHIDIncompleteException if the device does not have a name, report descriptor or the info bits set.

create_report(data, global_data=None, reportID=None, application=None)

Convert the data object to an array of ints representing the report. Each property of the given data object is matched against the field usage name (think hasattr) and filled in accordingly.:

mouse = MouseData()
mouse.b1 = int(l)
mouse.b2 = int(r)
mouse.b3 = int(m)
mouse.x = x
mouse.y = y

data_bytes = uhid_device.create_report(mouse)

The UHIDDevice will create the report according to the device’s report descriptor.

destroy()

Destroy the device. The kernel will trigger the appropriate messages in response before removing the device.

This function is called automatically on __exit__()

classmethod dispatch(timeout=None)

Process any events available on any internally registered file descriptor and deal with the events.

The caller must call this function regularly to make sure things like udev events are processed correctly. There’s no indicator of when to call dispatch() yet, call it whenever you’re idle.

Returns

the number of devices data was available on

property fd

The fd to the /dev/uhid device node

get_report(req, rnum, rtype)

Callback invoked when a process calls SetReport on this UHID device.

Return (0, [data bytes]) on success or (errno, []) on failure.

The default method always returns (EIO, []) for a failure. Override this in your device if you want GetReport to succeed.

Parameters
property info

The devices’s bus, vendor ID and product ID as tuple

property name

The devices HID name

open()

Called when a userspace client opens the created kernel device.

This message is sent by the kernel, to receive this message you must call dispatch()

output_report(data, size, rtype)

Callback invoked when a process sends raw data to the device.

Parameters
property phys

The device’s phys string

property pid

The device’s 16-bit product ID

property rdesc

The device’s report descriptor

set_report(req, rnum, rtype, data)

Callback invoked when a process calls SetReport on this UHID device.

Return 0 on success or an errno on failure.

The default method always returns EIO for a failure. Override this in your device if you want SetReport to succeed.

Parameters
start(flags)

Called when the uhid device is ready to accept IO.

This message is sent by the kernel, to receive this message you must call dispatch()

stop()

Called when the uhid device no longer accepts IO.

This message is sent by the kernel, to receive this message you must call dispatch()

property sys_path

The device’s /sys path

property udev_device

The devices’ udev device.

The device may be None if udev hasn’t processed the device yet.

udev_event(event)

Callback invoked on a udev event.

property vid

The device’s 16-bit vendor ID

exception UHIDIncompleteException

Bases: Exception

An exception raised when a UHIDDevice does not have sufficient information to create a kernel device.